/Engine/Source/Runtime/Engine/Classes/Engine/MicroTransactionBase.h
class UMicroTransactionBase : public [UPlatformInterfaceBase](API\Runtime\Engine\Engine\UPlatformInterfaceBase)
TArray< struct ...
AvailableProducts
The list of products available to purchase, filled out by the time a MTD_PurchaseQueryComplete is fired
FString
LastError
In case of errors, this will describe the most recent error
FString
LastErrorSolution
In case of errors, this will describe possible solutions (if there are any)